1. Field of the Invention
This invention relates to air regulators for use in diving apparatuses, and more particularly, to a first-stage air regulator characterized by a regulator housing containing a sliding piston which is provided with air slots positioned for transiently establishing air flow from a high-pressure air chamber, which is provided in one end of the housing, to an intermediate-pressure air chamber. The high-pressure air chamber receives air from a high-pressure air tank and transfers the air at reduced pressure to the intermediate-pressure air chamber, which distributes air through an air delivery hose to a second-stage regulator and mouthpiece. In a preferred embodiment air can additionally be distributed from the intermediate-pressure chamber to accessory items such as a lift bag, power inflator or a blow gun, through corresponding hoses.
Most conventional air pressure reduction regulators include a first stage for reducing air pressure from an air tank and moving air to a second-stage regulator, which feeds the air into a mouthpiece for breathing on demand by the user. One of the problems inherent in conventional first-stage regulators is wearing of the piston sealing surfaces and piston housing, thereby decreasing longevity of the apparatus. In these regulators the piston-end situated within the high-pressure chamber is flat and is forced up into a piston seat contained within the interior side of the housing wall. Long-term use of the regulator results in wearing of the piston-end and housing wall. The present invention reduces this problem by utilizing a rounded piston-end which contacts the housing wall in a correspondingly smaller surface area than that observed in conventional regulators, resulting in smoother operation and greater longevity of the apparatus. Additionally, in the present invention, that portion of the housing wall which is contacted by the piston-end is modified to define a housing cap which is threaded or otherwise fits into the regulator housing and can be removed for replacement of the worn housing cap itself or replacement of a worn piston, or both.
2. Description of the Prior Art
Various devices have been devised for directing a breathing gas from a storage tank to a breather apparatus. U.S. Pat. No. 3,714,941, dated Feb. 6, 1973, to Barry J. Kipling, details a "Medical Respirator" characterized by a gas container divided into two volumes by a movable member. Gas for the patient is expelled from a variable first volume by movement of the member, responsive to an increasing volume of patient gas flowing into the second volume. A switch controls the time-flow of gas from the respirator to the patient. U.S. Pat. No. 4,436,090, dated Mar. 13, 1984, to Philip H. Darling, describes a "Piston-Acutated, Pilot Valve-Operated Breathing Regulator" for use in a resuscitator or respirator. The breathing regulator includes a pressure-responsive piston which provides an outlet for exhalation and acts directly on a valve seat to open a pressurized gas pilot valve during inhalation. The piston is moved to open the pilot valve by inhalation suction, while a one-way valve automatically blocks the exhalation path during inhalation. U.S. Pat. No. 4,889,115, dated Dec. 26, 1989, to Enrico D. Bozano, discloses an "Air Regulator For Breathing Apparatus" characterized by the second stage of a regulator, including a first airflow circuit controlled by a monostat diaphragm which permits the flow of the minimum required amount of air upon each act of breathing, with minimum effort, and a second airflow circuit combined with the first circuit which operates to supply a supplementary amount of air to meet any additional need of the user. U.S. Pat. No. 5,038,770, dated Aug. 13, 1991, to Warren E. Perkins, discloses "Fail-Safe Systems for Respirating Gas Delivery Devices" for use with pulse dose respirating gas delivery devices to provide a continuous, metered flow of oxygen to a patient in the event of delivery device malfunction or a power failure. A piston is resiliently biased near one end of a cylinder and is adapted for receiving the force of pressurized gas in opposition to the biasing force of the piston and in synchronization with doses of respirating gas produced by the delivery device. That force is subsequently removed in coordination with the delivery of a gas dose to the patient. U.S. Pat. No. 5,052,383, dated Oct. 1, 1991, to Jean-Marie Chabert, describes a "Device for Supplying Breathing Gas to a Diver". A pressure-reducing valve is opened and closed by a piston actuated by an extended rod, the end of which is coupled to an articulated control lever which driven by a diaphragm. By increasing the distance from the articulated lever through the rod to the pressure-reducing valve, the risk of icing caused by cooling energy generated at the pressure-reducing valve when the diver operates in very cold water, is eliminated.
It is an object of this invention to provide a new and improved, first-stage air regulator which is characterized by a piston slidably accommodated between a high-pressure air chamber and an intermediate-pressure air chamber contained within a cylindrical housing, the piston being provided with air slots which are adapted for transiently passing air from the high-pressure chamber to the intermediate-pressure chamber, where the air equilibrates with pressure applied to the piston by a spring and by the ambient water pressure and is then passed to a second-stage air regulator through an air hose.
Another object of the invention is to provide an air regulator for reducing air pressure flowing from an air tank to the mouthpiece of diving equipment, which air regulator includes a slotted piston having a rounded end and slidably mounted in a housing between a high pressure chamber and an intermediate pressure chamber, wherein air at high pressure is allowed to flow through the slots in the piston when the slots communicate with both the high-pressure chamber and the intermediate-pressure chamber and the air pressure in the intermediate pressure chamber balances spring and ambient water pressure exerted on the piston to facilitate air flow into the mouthpiece.